Shaped articles of polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polycarbonate, polystyrene or the like are lightweight and strong against dropping and impact shock and, as compared with glass and ceramics, they are highly safe, and therefore, they are much used in various fields as packing containers. In particular, stretch blow-molded bottles of polyester resin such as typically polyethylene terephthalate are excellent in their transparency, surface glossiness, chemical resistance and inner pressure resistance, and therefore generally have properties advantageous for packing containers. Accordingly, they are much used in various fields of foods, detergents, etc.
Stretch blow molding comprises stretch-blowing preform inserted in a blow mold to give a stretch blow-molded article having a predetermined shape. In this, a label may be previously fitted inside the blow mold, and the label may be stuck to the surface of the stretch-blow molded article along with stretch blowing. This is in-mold labeling molding (for example, JP-A 2002-355886), and this is in fact much used in many aspects.
On the other hand, with the establishment of a law about promotion of separated collection and re-commodification for container packing (Container Packing Law for the Promotion of Utilization of Recycled Resources), recycling of shaped article is a social demand Accordingly, a technique of separating a label from a shaped article and recycling the shaped article has been proposed (for example, JP-UM-A 06-55727).
According to the technique, however, the label could not be completely stuck to the shaped article, and therefore the technique has a drawback in that the label may be spontaneously peeled off. When much paste is used for enhancing the adhesion, then the paste may remain on the shaped article after the label has been peeled off from the shaped article, and this is also defective in that the article could not be recycled.